JSR303和拦截器

目录

1.JSR303

导入pom依赖：

后端：

前端：

2.拦截器

OneHandlerInterceptor：

HelloController:

springmvc-servlet的配置:

               拦截器链

TwoHandlerInterceptor：

springmvc-servlet的配置

3.登录权限控制 

前端：

后端：

---

1.JSR303

导入pom依赖：

      org.hibernate

      hibernate-validator

      6.0.7.Final

    

后端：

clazz实体类：

package com.xbb.ssm.model;
 
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
 
/**
 * @NotNull ：作用于基本数据类型
 * @NotEmpty    作用于集合
 * @NotBlank    作用于字符串
 */
public class Clazz {
    @NotNull(message = "班级编号不能为空")
//    @Size(max = 100,min = 10,message = "大小必须在10至100之间")
    protected Integer cid;
 
    @NotBlank(message = "班级名不能为空")
    protected String cname;
 
    @NotBlank(message = "班级教员老师不能为空")
    protected String cteacher;
 
    protected String pic;
 
    public Clazz(Integer cid, String cname, String cteacher, String pic) {
        this.cid = cid;
        this.cname = cname;
        this.cteacher = cteacher;
        this.pic = pic;
    }
 
    public Clazz() {
        super();
    }

控制层ClazzController：

//    给数据添加服务端校验
    @RequestMapping("/valiAdd")
    public String valiAdd(@Validated Clazz clazz, BindingResult result,HttpServletRequest req){
//        如果服务端验证不通过，有错误
        if(result.hasErrors()){
//            服务端验证了实体类的多个属性，多个属性都没有验证通过
            List fieldErrors = result.getFieldErrors();
            Map map = new HashMap<>();
            for (FieldError fieldError : fieldErrors) {
//                将多个属性的验证失败信息输送到控制台
                System.out.println(fieldError.getField() + ":" + fieldError.getDefaultMessage());
                map.put(fieldError.getField(),fieldError.getDefaultMessage());
            }
            req.setAttribute("errorMap",map);
        }else {
            this.clazzBiz.insertSelective(clazz);
            return "redirect:/clz/list";
        }
        return "clzEdit";
    }

前端：

clzEdit.jsp：

<%--
"${pageContext.request.contextPath }/clz/${empty b ? 'add' : 'edit'}" method="post">--%>
"${pageContext.request.contextPath }/clz/${empty b ? 'valiAdd' : 'edit'}" method="post">
    id:"text" name="cid" value="${b.cid }">"color: red;">${errorMap.cid}
    cname:"text" name="cname" value="${b.cname }">"color: red;">${errorMap.cname}
    cteacher:"text" name="cteacher" value="${b.cteacher }">"color: red;">${errorMap.cteacher}
    "submit">

效果展示：

2.拦截器

什么是拦截器？

SpringMVC的处理器拦截器,类似于Servlet开发中的过滤器Filter，用于对处理器进行预处理和后处理。

OneHandlerInterceptor：

package com.xbb.ssm.intercept;
 
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
 
public class OneHandlerInterceptor implements HandlerInterceptor {
 
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//        预处理
        System.out.println("[OneHandlerInterceptor] . preHandle");
        return true;
    }
 
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
//       后处理
        System.out.println("[OneHandlerInterceptor] . postHandle...");
    }
 
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
//        完成后执行
        System.out.println("[OneHandlerInterceptor] . afterCompletion...");
    }
}
 

HelloController:

package com.xbb.ssm.web;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
 
/**
 * @author 冰冰
 * @create 2022-08-19 19:21
 */
@Controller
public class HelloController {
 
    @RequestMapping("hello")
    public String hello(){
        System.out.println("进入业务方法...");
        return "index";
    }
}
 

springmvc-servlet的配置:

    
        
        "com.xnx.ssm.intercept.OneHandlerInterceptor">
    

运行效果：

拦截器链

TwoHandlerInterceptor：

package com.xbb.ssm.intercept;
 
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * @author 冰冰
 * @create 2022-08-19 18:32
 */
public class TwoHandlerInterceptor implements HandlerInterceptor {
 
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//        预处理
        System.out.println("[TwoHandlerInterceptor] . preHandle");
        return true;
    }
 
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
//       后处理
        System.out.println("[TwoHandlerInterceptor] . postHandle...");
    }
 
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
//        完成后执行
        System.out.println("[TwoHandlerInterceptor] . afterCompletion...");
    }
}
 

springmvc-servlet的配置

    <mvc:interceptors>
        <mvc:interceptor>
            <mvc:mapping path="/**"/>
            <bean class="com.xbb.ssm.intercept.OneHandlerInterceptor">bean>
        mvc:interceptor>
        <mvc:interceptor>
            <mvc:mapping path="/clz/**"/>
            <bean class="com.xbb.ssm.intercept.TwoHandlerInterceptor">bean>
        mvc:interceptor>
    mvc:interceptors>

效果

3.登录权限控制 

前端：

login.jsp：

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2022/8/19
  Time: 19:55
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Titletitle>
head>
<body>
登录界面
body>
html>
 

后端：

LoginController：

package com.xbb.ssm.web;
 
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
 
import javax.servlet.http.HttpServletRequest;
 
/**
 * @author 冰冰
 * @create 2022-08-19 19:52
 */
@Controller
public class LoginController {
 
    @RequestMapping("/login")
    public String login(HttpServletRequest request){
//        登录成功需要保存用户信息
        String uname = request.getParameter("uname");
        if("zhangsan".equals(uname)){
            request.getSession().setAttribute("uname",uname);
        }
        return "index";
    }
 
    @RequestMapping("/loginout")
    public String loginout(HttpServletRequest request){
        request.getSession().invalidate();
        return "index";
    }
 
}
 

效果